A wire of resistance 10 ohms is drawn out to three times its
original length. The new resistance will be
(1) 90 ohm
(2) 10 ohm
(3) 30 ohm
(4) 120 ohm
Answer Posted / harsh dubey
R=RHO*L/A
MULTIPLY AND DIVIDE BY L
R=RHO*L*L/A*L
AS RHO AND VOLUME(A*L)IS CONSTT.
SO
WE HAVE,
R2/R1=square of (L2/L1)
as increased by 3 times,putting L1=3L2
WE HAVE,
R2=9R1
OR
R2=square of (n)*r........
so correct answer is=90ohm
Is This Answer Correct ? | 8 Yes | 2 No |
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